Continuous motion packaging machines, such as those machines which package articles such as beverage containers or food containers, typically group a selected number of articles into a desired configuration, and package those articles in a carton or carrier formed from a paperboard blank. In the example of beverage containers, such as bottles or cans, the articles are grouped into a predetermined configuration, and either moved singularly or in mass into an open paperboard blank. Otherwise, the paperboard blank is folded around the preconfigured article group. In either case, the packaging of the article group into the paperboard blank occurs while the article group is being conveyed along a path of travel from an infeed area to an outfeed area. This allows the articles to be packaged in a continuous operation, which normally carries on without interruption.
During or after this packaging step, various operations that require mechanical engagement by the packaging machine with the carton can occur. These operations may differ, depending upon the type of carton being utilized. Such carton engaging operations include punching certain areas of the carton, pushing into the carton and folding flaps into a particular orientation, bending the carton, or pushing opposed portions of the carton together in order to complete the article packaging step. In many of these operations, a machine component must engage a specific area or part of a carton in a particular manner to accomplish the desired process step. Considering that the operation must be accomplished while the carton is in continuous movement along a path of travel, often at high speeds, and that only a specific area must be engaged, the engaging mechanism must be designed to operate in timed relationship with the moving cartons. Additionally, some engaging actions or moving cartons tend to adversely impact the cartons, for example, by tearing portions of the cartons, since the cartons are being continuously pushed along by another mechanical device as the device is engaged.
Since typically the engagement operation takes a certain amount of time to complete and is not accomplished instantaneously, it is known that the engaging device must track the carton movement for a sufficient time to enable the process step to be accomplished. This allows, for example, an engaging device to be pushed into the carton, manipulated to accomplish the desired result, and then retracted from the carton, all of which steps take a certain amount of time, while the device is being moved along the path of travel in synchronization with the carton.
One such mechanism for accomplishing this is disclosed in U.S. Pat. No. 4,563,853 to Calvert. This mechanism discloses a device which engages a carton to effect folding of a leading and a trailing flap. Considering that the entire process step requires a specific amount of time to fully complete, the mechanism is designed to track the carton movement for at least the time required to complete the operation. The device is mounted onto a chain conveyor which is driven along the carton path of travel, and in timed synchronization with and aligned with specific areas of the carton. Carton engaging devices which are mounted onto such an elongate drive chain driven along the path of travel, however, include inherent problems. One problem resides in the fact that such systems are not readily interchangeable or adjustable to accommodate various carton sizes or shapes. For example, in many packaging machines now marketed, the machine is selectively adjustable to package various bottle sizes, styles, and shapes. Such an adjustment to a different carton necessarily will change the spacing of successive cartons and the operation required by the carton engaging apparatus. More specifically, the carton engaging pin of a tabbed locking mechanism will be spaced and timed differently for a carton comprising three rows of products than for a carton comprising four rows of products. Changeover to engage other types of cartons may require either disassembly and reassembly of the entire conveyor, or the inclusion of a chainphasing mechanism.
Another type of carton engaging apparatus of the prior art is disclosed in U.S. Pat. No. 4,612,753 to Taylor et al. This patent discloses a tab locking mechanism which utilizes a rotary wheel and cam arrangement, driving spaced carton engaging mechanisms, rather than the elongate chain conveyor of the prior art. The device utilized in U.S. Pat. No. 4,612,753 includes individual tab locking mechanisms or folders which are circumferentially spaced around a drive wheel, and each of which are radially movable with respect to the drive wheel axis. The device also includes brackets or fingers which were biased apart to complete the folding movement. Such rotary cam and drive wheel mechanisms provide for easier and quicker changeover to accommodate different carton styles and sizes, and eliminate the chain conveyor and its many associated elements.
Another device which utilizes the essentially identical concept of U.S. Pat. No. 4,612,753, is disclosed in PCT Patent Application No. PCT/US94/10787. The device disclosed in this application, however, forces the spaced, circumferentially mounted article engaging devices into the carton by forming the devices into a star arrangement and placing the main drive wheel directly adjacent to the carton. The drive wheel is rotated in order to angularly force the cone shaped engaging portions into the carton side wall. Thereafter, just as in the prior disclosure to Taylor, the actuating device is moved radially out from the drive wheel to spread apart two fingers and complete the folding operation. As the drive wheel continues to be turned, the actuating mechanism is pulled back into the wheel along its fixed, stationary radial line. One drawback with the device disclosed in this PCT application is that the actuating mechanism and the pivotal fingers are only in normal relationship with the moving carton at a single point in time, as the carton is transported past the engaging device in its continuous movement along the path of travel. This provides a tendency for the carton to be torn or otherwise undesirably impacted during the entering of the carton by the pivotal fingers and especially during the exit of the carton of the pivotal fingers when the mechanism is not at a substantially normal orientation with respect to the carton side wall.
Therefore, while the rotary carton engaging devices have been developed to provide better ease of adjustment or changeover, the devices nevertheless include drawbacks not found in prior chain devices, that is, their limitation to an angular movement and inefficient entry and exit from the carton due to the fixed rotation of the carton engaging device mounted to the drive disk or wheel.